Symptoms of autism in ADHD : a familial trait in a subset of children with ADHD which correlates with comorbid oppositional defiant disorder, conduct disorder and motor disorder

Abstract

Introduction; This study examines autism symptoms in a sample of children with ADHD, in their siblings, and in a control sample. Study sample: 821 children with ADHD, combined type who were participating in the International Multicentre ADHD Genetics (IMAGE) study and their 1050 siblings were studied. A control sample of 149 children was also studied. Measurements: Symptoms of ADHD and of comorbid disorders were assessed using parent and teacher Conners’ rating scales, the Strengths and Difficulties Questionnaires and the Parental Account of Children’s Symptoms semistructured interview. The Social Communication Questionnaire (SCQ) was used to measure symptoms of autism in the ADHD sample, the sibling sample and normal controls.